GtkBox: don't propagate the expand child property

The intention of the expand widget flags was to in fact propagate
legacy expand child properties as well. Due to implementation errors,
this was only happening in some cases, but not in others. To avoid
breaking old code assuming traditional expand flag behavior, this
commit removes all attempts to propagate GtkBox::expand.

This was discussed in
https://bugzilla.gnome.org/show_bug.cgi?id=698656 and
https://bugzilla.gnome.org/show_bug.cgi?id=628902

This patch was written by Tristan Van Berkom.

diff --git a/README.in b/README.in
index 851106417954401e97c90e24f5d6cbda50884df0..c002e115ebac6eb1fef27c85fe17decf722b25ab 100644 (file)
--- a/README.in
+++ b/README.in
@@ -81,6 +81,13 @@ Release notes for 3.10
   setups (not multi-monitor!) are very rare nowadays. If you really
   need multiple X screens, open them as separate displays.
 
+* The behavior of GtkBox::expand has been changed to never propagate
+  up. Previously, this was happening inconsistently. If you want the
+  expand to propagate, use the GtkWidget h/v expand properties.
+  If you experience sizing problems with widgets in ported code,
+  carefully check the expand and fill flags of your boxes.
+
+
 Release notes for 3.8
 =====================
 

diff --git a/gtk/gtkbox.c b/gtk/gtkbox.c
index e60fb4fa90457a91f051706d8973d32ab43c08e8..94e89073cc47ea86ee747c4477b1b811330a0643 100644 (file)
--- a/gtk/gtkbox.c
+++ b/gtk/gtkbox.c
@@ -150,9 +150,6 @@ struct _GtkBoxChild
 static void gtk_box_size_allocate         (GtkWidget              *widget,
                                            GtkAllocation          *allocation);
 
-static void gtk_box_compute_expand     (GtkWidget      *widget,
-                                        gboolean       *hexpand,
-                                        gboolean       *vexpand);
 static void gtk_box_direction_changed  (GtkWidget        *widget,
                                         GtkTextDirection  previous_direction);
 
@@ -230,7 +227,6 @@ gtk_box_class_init (GtkBoxClass *class)
   widget_class->get_preferred_height_for_width = gtk_box_get_preferred_height_for_width;
   widget_class->get_preferred_height_and_baseline_for_width = gtk_box_get_preferred_height_and_baseline_for_width;
   widget_class->get_preferred_width_for_height = gtk_box_get_preferred_width_for_height;
-  widget_class->compute_expand                 = gtk_box_compute_expand;
   widget_class->direction_changed              = gtk_box_direction_changed;
 
   container_class->add = gtk_box_add;
@@ -285,6 +281,9 @@ gtk_box_class_init (GtkBoxClass *class)
    * Note that the #GtkWidget:halign, #GtkWidget:valign, #GtkWidget:hexpand
    * and #GtkWidget:vexpand properties are the preferred way to influence
    * child size allocation in containers.
+   *
+   * In contrast to #GtkWidget::hexpand, the expand child property does
+   * not cause the box to expand itself.
    */
   gtk_container_class_install_child_property (container_class,
                                              CHILD_PROP_EXPAND,
@@ -779,53 +778,6 @@ gtk_box_size_allocate (GtkWidget     *widget,
     }
 }
 
-static void
-gtk_box_compute_expand (GtkWidget      *widget,
-                        gboolean       *hexpand_p,
-                        gboolean       *vexpand_p)
-{
-  GtkBoxPrivate  *private = GTK_BOX (widget)->priv;
-  GList       *children;
-  GtkBoxChild *child;
-  gboolean our_expand;
-  gboolean opposite_expand;
-  GtkOrientation opposite_orientation;
-
-  opposite_orientation = OPPOSITE_ORIENTATION (private->orientation);
-
-  our_expand = FALSE;
-  opposite_expand = FALSE;
-
-  for (children = private->children; children; children = children->next)
-    {
-      child = children->data;
-
-      /* we don't recurse into children anymore as soon as we know
-       * expand=TRUE in an orientation
-       */
-
-      if (child->expand || (!our_expand && gtk_widget_compute_expand (child->widget, private->orientation)))
-        our_expand = TRUE;
-
-      if (!opposite_expand && gtk_widget_compute_expand (child->widget, opposite_orientation))
-        opposite_expand = TRUE;
-
-      if (our_expand && opposite_expand)
-        break;
-    }
-
-  if (private->orientation == GTK_ORIENTATION_HORIZONTAL)
-    {
-      *hexpand_p = our_expand;
-      *vexpand_p = opposite_expand;
-    }
-  else
-    {
-      *hexpand_p = opposite_expand;
-      *vexpand_p = our_expand;
-    }
-}
-
 static GType
 gtk_box_child_type (GtkContainer   *container)
 {